The maximum lactate production rate - What are the benefits of anaerobic tests?

Performance diagnostic tests to measure your aerobic performance are widely used. Less known are measuring methods for the assessment of anaerobic capacities.

Although these tests are sometimes offered commercially, a benefit to the athlete in current testing is questionable. Thus, either the duration of the test is questioned or it is generally pointed out that the VLamax can not be measured via the capillary blood. (1) This is due to the many factors influencing the rate of lactate formation and lactate elimination as well as the fundamental importance of lactate. (2)

The Wingate test

The Wingate test is an anaerobic test procedure that is widely used in training effects studies in particular. It is used z. T. also in the performance diagnostics. The athlete will be charged in this test within a short time (30 seconds). After a warm-up period of 5-10 minutes followed by a short break of a few seconds, the test person is loaded to the maximum. The performance is increased depending on the body weight. The maximum power is detected as a function of the speed, the resistance being set at approximately 7.5% of the body weight. At such a high level of stress, the athlete will reach maximum power shortly after the test starts, which will drop to the end of the test after peaking. The maximum power (peak power - PP) should be identical to the maximum alaktaziden performance. The energy is thus initially provided by the local storage of high-energy phosphates, adenosine triphosphate (ATP) and creatine phosphate (KP). In addition to the peak power, the average power within the 30-second interval, the so-called Mean Power (MP) is also measured. Even the lowest power value, the Lowest Power (LP), belongs to the recorded parameters.

Are 30 seconds enough?

The measurement of anaerobic capacities by the Wingate test is subject to various criticisms. First of all, it is criticized that the duration of the test is insufficient to reach the maximum capacity of endurance trained athletes. Different authors therefore tried to develop their own methods based on the 60-90 seconds test duration based on the Wingate test. (1) On the molecular biological level, however, there are many influencing factors that basically influence the informative value of anaerobic test procedures. This raises the question of whether, according to the current state of knowledge, it makes sense to apply a test procedure for detecting anaerobic energy provision.

The maximum lactate formation rate - A test procedure with statement?

In the field of performance diagnostics, the offer to measure the maximum lactate production rate has increased. The starting point is the idea to be able to detect differences between very good aerobic capacities with a low lactate formation rate, and to see high lactate formation rates as a reference to sprinting abilities. In cycling sports training methods are to be adjusted to the maximum lactation rate to compensate for weaknesses. The maximum lactate production rate (VLamax) should be lower in endurance-trained athletes, so as not to adversely affect aerobic metabolism, and higher in sprinters. Theoretically, anaerobic glycolysis - that is, carbohydrate metabolism without oxygen - achieves the highest activity in short-term loads of 15 seconds. In order to determine the maximum rate of lactation, maximum exercise on an ergometer within approximately 15 seconds is desired. After the end of the test, the lactate concentration is determined every 1-2 minutes - until the lactate concentration in the blood decreases again. By determining the maximum lactate concentration and the duration of the load, the maximum lactate formation rate is now determined:

VLamax = Lmax / t test

Due to the short exposure time, the lactate elimination should be neglected. It is thus assumed that the maximum value of the post-exposure lactate represents a reliable measure of the lactate formation rate. Unfortunately, this is not so because many aspects are not detected and cause the determination of VLamax to be prone to error.

The mix makes it!

A basic problem in detecting anaerobic capacity is that on the one hand there are anaerobic metabolic pathways that can do without the formation of lactate, while on the other hand lactate is an intermediate metabolite of anaerobic metabolism. However, it is not possible to delineate the two metabolic pathways. The anaerobic-alactic pathway of energy supply relies on high-energy phosphates, which are stored to a very limited extent in the working musculature. Creatine phosphate (KP) and adenosine triphosphate (ATP) are used to provide energy very quickly. Since these stores are exhausted after about 6-10 seconds, the body has to resort to other anaerobic metabolic pathways in order to be able to form further ATP as quickly as possible. The depletion and flow rate of the high-energy phosphates is thus a first factor influencing the anaerobic abilities and can not be quantified or measured in any of the known test methods. Statements on the rate of lactate formation and anaerobic-alactic acid capacities already have a high susceptibility to error due to this fact. Accompanying parameters such as ammonia are also unsuitable for inferring the anaerobic-alactic acid capacity, which can be demonstrated by studies that are not available. (3)

Lactate formation is not validly measurable in short tests

The lactate production rate in the musculature depends on many different factors. For example, a very important factor is the muscle fiber structure. For fibers that are primarily glycolytic, they can be four times the amount of lactate produced in primary oxidative muscle fibers. (2) The distribution of an important enzyme that catalyzes the production of lactate is also an important factor. The activity of lactate dehydrogenase (LDH) also differs greatly within the different muscle fiber types. But also the degradation of lactate within the muscle fibers depends on the structure of these fibers. Thus, muscle fibers that are characterized by oxidative effects and thus accumulate in endurance athletes start already at a lactate concentration of 1-2 mmol with the change from a net lactate release to the net lactate intake. (2) This determines the lactate intake and elimination and thus the blood lactate concentration. The lactate transport is determined by the affinity to the transporters and the transporter speed. (2) The transport capacity thus also influences the lactate accumulation and thus also the dynamics of the lactate. While in a step test with appropriate knowledge and in evaluation methods that take into account in particular the aerobic capacities, ie the basic lactate, individual trajectories can describe, measuring the maximum lactate formation rate reaches its limits here. In order to be able to make an exact statement about the VLamax, it would be necessary to measure the values ​​within the working musculature. This is currently impossible metrologically, so that the determination of VLamax on capillary blood from the ear or the fingertip as scientifically currently not be considered durable. The use in performance diagnostics is thus rather skeptical.

Laktatparadox

Lactate has long been considered a metabolic end product. However, studies show that in the trained muscles lactate can also be supplied to the aerobic energy supply, in which it is metabolized at the educational site and also at distant cells. (2) The musculature is thus the place where most of the lactate is again can be reduced. According to this, lactate serves as an energy source even at lower intensities of 55% of VO2max, so that the lactate oxidation increases strongly. (2)

Conclusion

Anaerobic test methods are only limitedly suitable for use in sports counseling. This is partly due to the metrological problems, but also on the other hand, the limited validity. With regard to lactate diagnostics, the lactate level test, which is still one of the standards of sports medicine, is suitable for identifying your training areas and demonstrating performance changes. (4)

Also read: What is my training area and how can I find it?

Dennis Sandig

Literature:

1. Journal of Sports Science and Medicine, 2003, vol. 2, pp. 151-157.

2nd Swiss Journal of Sports Medicine and Sports Traumatology, 2009, Vol. 57 (3), p.100-107.

3. German Journal of Sports Medicine, 2002, Vol. 53 (7 & 8), pp. 202-212.

4. Swiss Journal of Sports Medicine and Sports Traumatology, 2001, Vol. 49 (2), pp. 57-66.

Jargon:

Lactate - is produced during anaerobic carbohydrate oxidation

Oxidative - with oxygen

Glycolysis - Degradation of glucose

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